Control system for an oil burner



25, 1954 F. J. REUSCH, SR 3,145,761

CONTROL SYSTEM FOR AN OIL BURNER Filed Jan. 2, 1962 INVENTOR.

ATTORNEYS FREDERICK J. REUSCH, SR.

United States Patent 3,145,761 CONTROL SYSTEM FOR AN OIL BURNER Frederick J. Reusch, Sr., 637 Church St., New Bedford, Mass. Filed Jan. 2, 1962, Ser. No. 163,796

1 Claim. (Cl. 158-42.1)

This invention relates to an oil burner or more particularly the operating system of the oil burner.

Heretofore, when an oil burner exhausted its supply of oil, air filled the lead lines from a supply tank to the burner making necessary priming in order to start the oil burner. This priming was a rather messy and hazardous operation as blowbacks might cause damage or even cause the ignition of a fire.

One of the objects of this invention is to provide an apparatus which will make unnecessary the priming of a burner.

A more specific object of the invention is to stop the oil burner just prior to the exhaustion of the oil in the conduit which heretofore might become air bound upon exhaustion of the oil.

Another object of the invention is to provide an apparatus which will be self-sealing when the supply tank is full of oil.

Another object of the invention is to provide an alarm device in the form of a light which may indicate the condition of the supply of oil when the same is substantially exhausted.

Another object of the invention is to provide a unit control for both the oil burner and the switch for the light.

With these and other objects in view, the invention consists of certain novel features of construction as will be more fully described and particularly pointed out in the appended claim.

In the accompanying drawings:

FIG. 1 is a diagrammatic view illustrating the oil burner system with my improved apparatus installed;

FIG. 2 is an elevation partly in section of the float tank which is utilized for the control which I provide;

FIG. 3 is an elevation, with the cover removed, of a switch unit; and

FIG. 4 is a view similar to FIG. 3 of a modified form of switch unit.

In proceeding with this invention, I have tapped in to the oil conduit extending from the supply tank to the oil burner so as to lead oil from this conduit to a tank in which I locate a float which when in raised position with oil in the supply tank closes a switch located in the electric motor circuit for the oil burner so as to maintain the oil burner operating. However, should the oil in this tank reach a predetermined lower level, this float will upon reaching such a position in the tank cause a switch to be operated in the electric circuit of the oil burner so as to stop the oil burner prior to oil becoming exhausted from the conduit which connects the supply tank to the burner, thus making it unnecessary to prime this conduit which heretofore was necessary when the oil was completely exhausted from it and the conduit was filled with air.

With reference to the drawings, designates a furnace having an oil burner 11 driven by an electric motor 12 on a support 13 to which oil burner there is an oil conduit 14 leading from the fuel supply tank 15 with fuel 16 therein. In this conduit line there is the usual filter 17 connected to the supply tank as at 18 and oil is drawn from this filter through the T 19 which has the leg 20 thereon connected to a control tank 21 by means of an oil conduit 22.

This control tank 21 is in the form of a cup shape container 23 (see FIG. 2) having a top 24 attached by screws 25. An opening 26 in the top wall 24 receives a sleeve fitting 27 which has a tapered valve seat 28 at its lower end, while a tube 29 extends upwardly from its upper end. A float 30 is located in this control tank which float is equipped with a conical plug 31 of a shape and size to enter and engage the conical seat 28 when the float is in its upper position and provide a seal against the discharge of oil or liquid 32 in the control tank. A vent pipe 33 may extend from this top wall 24 to any height desired above the height of the supply tank 15. A rod 35 extends upwardly from the float 30 and the conical plug 31 through the tube 29 to a switch unit 36 as shown in FIG. 1, this rod serving to actuate a switch for the control of the motor 12.

The switch 36 shown in FIG. 3 has control leads 37 and 38 which are placed in the usual series control circuit of a burner as at 70 extending to the terminal block 49, and from there the leads 39 and 40 extend to a mercury switch 41 which is mounted upon a plate 42 pivoted as at 43 on the back wall 44 of the unit 36. This plate 42 is provided with an ear 45 through which the rod 35 extends with a sleeve 46 adjustably held on the rod 35 by set screw 47 so as to support the plate at the end remote from its pivot 43 in a desired location so that the mercury switch 41 will maintain an electrical connection between the leads 39 and 40 when the plate is in the raised position as shown in FIG. 3. However, when the float is lowered by reason of the drop of liquid 32 in the control tank 21 to a certain extent, then the mercury in the switch 41 will move to the opposite end of the container separating the electrical connection between 39 and 40 and stopping the burner motor.

This switching unit may also be considered to perform an additional function and light a lamp or more than one lamp or other signal if desired, such as designated at 50. Leads 51 and 52 which are placed in a usual series control circuit of this lamp are shown as entering the switch unit 36 and connected to the terminal block 49 where these leads from the block are designated 53 and 54 and connect to a mercury switch 55 on the plate 42. When the plate is in the raised position, this mercury switch 55 will have the mercury at the end of the tube, as shown, so that there will be no electrical connection between wires 53 and 54, but when the plate is swung about its pivot to a lower position, such as when the oil in the control tank 21 lowers to a predetermined amount, then the mercury will run to the right as shown in FIG. 3 and bridge the contacts between wires 53 and 54 so as to light the lamp 50.

It will be apparent that the control tank 21 will be placed at the proper level so that when the float 30 reaches the location of the dot-dash line 55 and the oil in the tank has lowered to a point substantially at the lower lead off tube 18, the burner will be stopped, leaving oil in the conduit 14 to the burner so that when the supply of oil is again replenished in the tank 15, the float 30 will rise, and as soon as it does rise, the light will go out, the motor for the burner will be electrically connected and will start.

As an alternate form of the switch unit 36, I have shown a unit 36' in FIG. 4 in which the plate now designated 56 is provided with mechanical contacts instead of mercury contacts, there being spring arms 57 and 58 extending from the terminal block 49 and an insulated roller 59 on the arm 56 so that when in raised position, the roller 59 will force the contacts 60 and 61 on the resilient arms 57 and 58 into contact, whereas when the arm is swung to a lower position, the roller will permit these contacts to separate. Further there are spring arms 62 and 63 which have contacts 64 and 65 with an insulated roller 66 on the arm which hold these contacts separated when the plate is in raised position but which upon the plate being swung about the pivot 43 will lower the roller 66 permitting the contact 65 to engage the contact 64 and complete the circuit to the light. By this arrangement mercury switches do not need to be used.

I claim:

In an oil burner system, an oil burner, an electric motor for operating the burner, an electric circuit therefor, an oil supply tank at an elevation to supply oil to said burner by gravity, an oil conduit from said tank to said burner, a control apparatus comprising a switch in said electric circuit to disconnect said electric motor and located at an elevation no higher than the top of the oil supply tank, means responsive to a low level of oil in said tank to operate said switch prior to exhausting oil from said oil conduit, said means comprising a tank with a float therein connected to the supply tank and at such location as to cause the level of the liquid therein to follow the level of the liquid in the supply tank, said float being connected to operate said switch, said second tank having a top with an opening therein, said top being located below the top of the supply tank, a rod carried by said float extending upwardly through said opening and a conical plug on said float to enter said opening and seal the same as the float rises in said tank and a vent tube from the top of the second tank extending to a height above said supply tank.

References Cited in the file of this patent UNITED STATES PATENTS 1,406,196 Londe Feb. 14, 1922 1,780,971 Chandler Nov. 11, 1930 2,127,422 Phaneuf Aug. 16, 1938 2,409,245 Black Oct. 15, 1946 2,495,571 Davis Jan. 24, 1950 2,496,467 Griifith Feb. 7, 1950 2,955,173 Kranz Oct. 4, 1960 3,017,921 Stierlin Jan. 23, 1962 

